This invention relates to new polymers containing amide linkages and to a process for preparing such polymers. More particularly, this invention relates to the polymerization of alpha, beta-unsaturated monocarboxylic acids or the ammonium salts thereof.
There are several known methods for producing nylon-3 type polymers using starting materials different from those of the present invention. For example, as described in U.S. Pat. No. 2,749,331, polyamides can be prepared from acrylamide by hydrogen transfer polymerization in the presence of a basic catalyst. Other processes for preparing polyamides employ beta-lactam and a ring opening polymerization (U.S. Pat. No. 3,220,983), condensation hydrolysis of beta aminopropionitrile (U.S. Pat. No. 3,499,874), condensation hydrolysis of oxydipropionitrile (Japan No. 68 27,617), thermal condensation of beta-alanine (U.S. Pat. No. 2,691,643) and the thermal polymerization of ethylene cyanohydrin (U.S. Pat. No. 3,125,353).
Most polyamides are produced by a condensation polymerization process. In other words, the polymerization occurs primarily by the reaction between pairs of functional groups, with water split out. For example, the thermal condensation of beta-alanine proceeds as follows: ##STR1##
It is also known that the inventive reactants, i.e., alpha, beta-unsaturated carboxylic acids and salts thereof, can be polymerized. This polymerization is a vinyl polymerization, (U.S. Pat. No. 2,956,046), and results from a free radical mechanism, the polymerization taking place across a double bond without formation of a side product. This reaction proceeds as follows: ##STR2##
It is an object of this invention to provide a novel process wherein high yields of new polyamides can be directly produced from alpha, beta-unsaturated monocarboxylic acids or the ammonium salts thereof.